Cosmology
has the potential to test fundamental physics through the discovery of
new particles (e.g. dark matter) and new fields that governed the
Universe's expansion at early times (inflation). One of the most
powerful tools available for such studies is the Baryon Acoustic
Oscillation (BAO) signal. Many future galaxy redshift surveys are
designed with BAO as their main science driver. In this talk, I will
introduce two recently developed extensions to the standard BAO
analysis. The first extension uses the BAO analysis pipeline for a
search for primordial features, which can be used to constrain
inflationary models. The second extension uses the phase of the BAO to
constrain the effective number of relativistic particles in the early
Universe. Given the robustness of the BAO feature and the hugely
improved constraints we can expect from future surveys like DESI and
Euclid, these extensions have the potential to significantly enrich the
science output of these experiments.